1 Correction to: Applied Physics A (2019) 125:445 https://doi.org/10.1007/s00339-019-2739-x

Dear readers,


In the originally published version of this article the acknowledgement was missing.


It should read as follows:


Acknowledgements The authors would like to thank Prof. R. El-Mallawany, Faculty of Science, Physics Department, Menoufia University, Egypt, for his advises, support, and valuable comments to achieve this work.

We apologize for this error.

The original article has been corrected.